Transmission and reception of pictures



Feb. 19, 1935. KELL 1,992,009

TRANSMISSION AND RECEPTION OF PICTURES Filed April 15, 1929 Inventor'- Rag D. Ke LL,

allo

His Attorney.

Patented Feb. 19, 1935 TRANSMISSION AND RECEPTION F PICTURES Ray D.'Kell, Scotia, N.

Y., assignor to General Electric Company, a corporation of New York Application April 15, 1929, Serial No. 355,028 I 11 Claims.

My invention relates to the transmission and reception of pictures, and has for its principal object the provision of an improved apparatus and method of operation whereby a comparatively low intensity source of light may be utilized to produce a comparatively bright picture.

It is known that light sources, such as gaseous conduction lamp of the type disclosed by Letters Patent of D. McFarlan Moore, No. 1,316,967, may be utilized to produce light which is modulated in accordance with the shades of the successive elemental areas of a picture. Such a lamp has the advantage that its light is readily modulated but, as usually constructed, is not always capable of producing a picture of the desired brilliancy. In accordance with my invention,- this difficulty is obviated by the provision of an im-.

proved apparatus and method 'of operation whereby the pictures produced by a plurality of light sources subjected to the same control signal are superimposed on each other. f

My invention will bebetter understood from the following description when considered in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

The drawing illustrates a receiving apparatus wherein my invention has been embodied.

This apparatus includes a picture receiving member 10 upon which the light of a plurality of sources 11, 12 and 13 is projected through scanning'means shown as a lens disk 14. This scanning disk isprovidedwith a plurality of spirally arranged lenses l5 and is arranged to be rotated by a motor 16. With this arrangement, the light sources 11, 12 and 13 produce on the picture receiving member 10 images which are displaced from one another and are simultaneously swept across successive areas of the member 10 due to rotation of the disk 14.

Electrical impulses modulated in accordance with the shade of the succesive elemental areas of the transmitted picture are received by an antenna 17 and a radio receiver 18. These signal impulses are applied to the lamp 11 through a space discharge device or power tube 19, to the lamp 12 through a phase control device 20 and a space discharge device or power tube 21, and to the lamp 13 through a phase control device 22 and a space discharge device or power tube 23'. Various types of phase control devices are well known to those skilled in the art. Any suitable phase control device, for example, such as that disclosed by United States Patent of Ernst F. W. Alexanderson No. 1,655,041, may be utilized for controlling the phase of the signal supplied to the light source 12 and 13. Another suitable phase control device is that disclosed by the Alexanderson Patent No. 1,719,866, July 9, 1929.

As previously indicated the lamps 11, 12 and 13 produce on the member 10 images which are displaced from one another by distances dependent on the spacing between the lamps. In the absence of the phase control devices 20 and 22, the lamps would therefore produce on the member 10 pictures which were overlapped and displaced from I one another. The function of the phase control devices 20 and 22 is to make these different pictures coincide with one another.

Thus if the picture produced by the lamp 11 is properly framed, the signal received through the antenna 17 is shifted in phase by the device 20 sothat when it is applied to the lamp 12 this lamp produces on the member 10 a picture which coincides with that produced by the lamp 11. Likewise the received signalis so shifted in phase by the device 22 that the picture produced by the lamp 13 also coincides with that produced by the lamp 11. Under these conditions, the lamps 11, 12 and 13 simultaneously produce different parts of coinciding pictures and the brilliancyv of the picture is much; greater than that realized fromthe use of a single lamp.

The embodiment of the invention illustrated and described herein has been selected for the purpose of clearly setting forth the principles involved. Itwill be apparent, however, that the invention is susceptible of being modified to meet the different conditions encountered in its use and I therefore aim to cover by the appended claims all modifications within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. The combination of a plurality of light sources, scanning means for producing separate 7 relatively displaced images of said sources, signal receiving means arranged to subject said sources each to the same electric impulses dependent on the shading of the successive elemental areas of a picture to be reproduced and electric time delay means connected with certain of said sources for causing said images to appear superposed.

2. The combination of a plurality of light sources, scanning means for producing images of the respective sources in different scanning lines, signal receiving means arranged to subject the sources each to the same electric impulses dependent on the shading of the successive elemental sources, a receiving member, scanning means for imaging each of said sources on said member,

means for receiving signal impulses which'vary; in accordance with the shade of the successive elemental areas of a picture to be reproduced, and

means connected between said means for receiv-' ing signal impulses and said light sources for causing each signal impulse to be applied to each of said sources at different. respective times in-accordance with the position of said sources-withrespect to one another.

5. The combination of means for receiving a" signal which varies in accordance with the shade of the successive-elemental areas of a picture'to be reproduced, a plurality of space-discharge devices, a phase control device, and a plurality of light sources one of which is connected to said signal receiving means through one 'ofsaid space discharge devices and another of which is connected to said signal receiving means through another of said space discharge devices and said phase control means." l

6. The combination of means for receiving a signal which varies in accordance with the shade of successive elemeritalareas of a picture-to be reproduced, a plurality ofspace discharge and phase control devices, and aplurality of'light sources one of which is connected to said signal receiving means through one of said space discharge devices and one of saidphase control devices and another of which is connected to said signal receiving means through another of said space discharge devices and another of said phase control devices.

'7. The combination of a plurality oflight sources, means for receiving-asignal which varies in accordance with the shade of the'successive elemental areas of a picture to-be-reproduced, means controlled by said signal -for-causing the entire received signal to be applied successively to each of said sources, a picture receiving member, and means for causing the light of said sources to scan said member.

8. In the art of receiving television signals the steps comprising receiving television signals, transmitting said signals over a plurality of independent circuits, delaying the signals in one circuit with respectsto signalsvim other. cimuits by a-time-period-le'ss thanrthe time period required for a complete scanning of the image, and controlling a source of light by the signals in each circuit, whereby the sources of light completethe same cycles of variations in delayed sequences.

9'. .In; the artofJ-television, the steps of producing-axtelevision image comprising receiving a series .of television signals, repeating the effects ofthe signals a plurality of times within the period of persistance of vision, and producing from each repetition beams of light coordinated to predetermined imageareas and successively varied according to: the signalvariations.

10. A'televisionreceiver comprisinga plurality of sources of light, means to control each source with a time delay period'less than thescanningperiod according to successive portions of the same television signal wave, and synthesizing means to direct the time separated beams of light from each of the controlled sources over like-predetermined areas within the period of persistance of vision to form the television image,

11. In a system for producing images of a sub-; ject which has been scanned to produce a trainof signals representative of thevarying intensities of light and shadow of each elemental area thereof, a viewing screen, aplurality of light producing means arrangedso as to simultaneously illuminate independent separated elemental areas of the screen, means to cause the light produced by taneously represented by each light spot :on the screen.

RAY D. 

